lansing



Feb. 17, 1931. H, MATT 1,793,451

THERMOSTA TIC CONTROL FOR HEATERS Filed Nov. 25, 1927 J5 s E i :7 16% i x 2 I 2 1 3 irufaivf y QZZ'Z s Patented Feb. 17, 1931 UNITED STATES. PATENT OFFICE.

nownnn I. run, or LANSINQJEIGHIGAN, ASSIGNOB 'ro moron wnnnn conroa'a- T1011, or LANSING, MICHIGAN, a CORPORATION or MICHIGAN 'rnsnuos'rnrrc ooN'rnon for. Humans Application fled November 25, 1927. Serial No.

The present invention has for its object the thermostatic control of fuel burners and particularly as applied to water heaters, although it is equally applicable tohouse heat ng systems.

Obviously variations in details-from the structure herein shown and illustrated by way of exemplification will readily suggest themselves to one skilled in the art wlthout departure from the spirit of the invention as set forth in the appended claims.

. In the drawing, showing an improved embodiment,

Fig. 1 is a section through a water heater equipped with the invention;

' Fig. 2 is an enlarged sectlonal detall of a thermostat; and

Fig. 3 is across section through the needl valve near its operative point.

A water heater, the details of which form no part of the present invention, is indicated at 11 with a main body of water 12 heated by means of the burner 13 fed with fuel from the tank 14 by way of the fuel line 15. Interosed in the fuel line is a head-determining oat chamber 16 and level-determining float chambers 17' and 18, the details of which head and level controls form the subject matter of a coending application, Case No. 7092.

stat 19 in the form of a tubular body having at one end an enlarged valve-containing chamber 20 with an inlet port 21 and an outlet port 22 for the fuel.

A shell 23 isseated, preferably removably,

in that end of the tubular body 19 opposite the valve chamber 20 and has its extreme end closed by the screw plug1 24. Within this shell, forming a part of t e tubular body, is

40 mounted a bimetallic thermostatic bar 25, the

component parts of which are unequally affected by variations in temperature. An ex- ,tension arm 26 extends from the bimetallic r bar' through the tubular body' to a point of articular connection with the needle valve stem 27, the end 28 of the arm engagin within a cage 29 carried by the valve stem, w ereby as thearm moves under the impulse of the bimetallic members the valve stem will be seated and lifted from its seat. The adjustmentof the valve is provided for by a kerf 30 in the'upper threaded end of a spindle 27a, access being had thereto by means of a screw plug 31. The operative lower end 32 of the needle valve stem has a limited area of its seating face formed eccentric to theseat, preferably by flattening as indicated at 33.

Thatend of the tubular body 19 opposite the valve chamber 20 is shown as screw threaded at 34 for insertion in a boss 35 of the inner wall 36 of the heater whereby the extreme end of the tubular body formed by the shell 23 is projected within the heated area here represented as the body of water 12.

It will be readily understood that the rise in temperature of the water 12 will act upon the thermostatic bar 25: and its extension arm 26 to releasethe needle valve and permit it.

to drop to its seat; whereas a lowering of the temperature will,- through the same means, cause a lifting of the needle valve fronrits seat, thus controlling the flow of fuel to the burner to an extent calculated to maintain the Water at approximately'a desired temperature.

Inasmuch as 1t Wlll be desired to maintain a constant pilot flame at the burner, a 'reduced sup ly of fuel to the burner must bev provided 0 disposed in the feed line is a thermoor even when" the needle valve is closed. This is accomplished by the provision of the fiat area on the needle valve which permits of a bleeding of the valve and the passage of suflicient fuel to maintain the pilot flame.

I claim:

1. In a thermostatic control, the combination with a water heater,'a burner, and a liquid fuel line, of a tubular body having at one end an enlarged chamber with an inlet and an outlet port for the fuel, a needle valve seated within the enlarged chamber in the outlet port, a relatively short bimetallic thermostatic bar mounted in the other end of the tubular body, that end of the body containing the thermostatic bar being threaded for insertion through a heater wall into the heated water, and an articulated extension arm from the bar into articular connection tions in the water temperature, the needle valve provided with a flattened area on its seating face whereby to provide a constant reduced supply of fuel to a pilot flame when 5 the'valve is seated.

2; In a thermostatic control, the combination with a heater, a burner, and a liquid fuel line, of a tubular body having at one end a separate tubular member therewithin and at the other end an enlarged chamber with an inlet and an outlet port for the fuel, a needle valve seated inone of the ports, saidneedle valve having a portion flattened eccentricv t0 the seat to afford a by-pass, a relatively short bimetallic thermostatic'bar mounted in the separate tubular member and subject to contact with the liquid fuel and to the influence. of the fluid within the heater, that end of the tubular body containing the separate tubular member and thermostatic bar being threaded for engagement with the wall of a heater, and an articulated connection disposed be tween the needle valve stem and the end of the thermostatic bar, said connection extending through the tubular member, whereby tocontrol the flow of fuel to the burner in response to the temperature within the heater.

3. In a thermostatic control, the combination with a water heater, a burner, and a liquid fuel line, a hollow body having its interior in communication With the liquid fuel line, a needle valve disposed within the hollow body and controlling the outlet port therefrom, a thermostat within the hollow body, an articulated connection between the thermostat and the needle valve, the thermostat being mounted in a separate hollow member disposed within the Water of the heater and subject to the temperature thereof to open and close the valve in response to temperature fluctuations within the water heater, whereby to control the flow of fuel to the burner, the needle valve being pro vided with an eccentric area on its seating face to provide a constant reduced supply of fuel to a pilot flame when the needle valve is seated.

In testimony whereof I have hereunto subscribed my name.

HOWARD I. PIATT. 

